In medieval times, the south bank of the River Thames in London was full of seedy theaters, brothels and scoundrels. But centuries later, it has become one of the world's finest centers for the arts. Recent plans to expand the arts center has revealed a uniquely, contemporary conflict. As NPR's Philip Reeves reports, this conflict is reviving grassroots activism in Britain's capital.

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UNIDENTIFIED MAN: Do you know your blues scale? Havana and Mike, do you know your blues scale, in C?

PHILIP REEVES, BYLINE: Some young musicians are learning some old skills.

UNIDENTIFIED MAN: So I want to hear evidence of some flat thirds, right, some fourths, all that stuff. OK?

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REEVES: Eighteen-year-old Cherise Adams-Burnett is practicing her vocals. Cherise hopes to turn professional one day. She attends these sessions every week and says they're life-changing.

CHERISE ADAMS-BURNETT: Coming here and experiencing jazz and realizing it's really all about just nurturing your musical skill meant absolutely everything to me, and I've truly found who I am.

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REEVES: We're in the Southbank Centre in the middle of London. This is one of the world's most prestigious arts centers. Yet this jamming session by young musicians with tomorrow's warriors is in a cramped and cluttered room.

ADAMS-BURNETT: It's a relatively large box, with a piano and some chairs. I think that's a good way of saying it, a box.

REEVES: The lack of rehearsal space is hardly surprising when you consider what else is here.

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JUDE KELLY: We do put on the great world figures, you know, the great orchestras, the great musicians, the great artists of all kinds. And it really is one of the great people spaces of the world for culture.

REEVES: Jude Kelly is the Southbank Centre's artistic director. The place has four resident professional orchestras, including the London Philharmonic.

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REEVES: It covers 21 acres beside the Thames next to the London Eye of Waterloo Bridge. The center has some world-famous venues, including the Royal Festival Hall, the Hayward Gallery and the Queen Elizabeth Hall. Kelly believes the Southbank Centre should also play a wider role by serving every part of society, nurturing arts right down to the grassroots.

KELLY: Unfortunately, history has tended to siphon art off and say, well, it belongs to the few, not the many. And our whole impulse is to say, no, it belongs to the many and not the few.

REEVES: To help attract the many, the center's planning to build a new wing, including three stories of space for local schools and a glass pavilion. The Southbank Centre stands on some of the world's most valuable real estate, yet some of the neighborhoods nearby are among the poorest in London.

JANINE IRONS: I suppose the issue here is, you know, choices have to be made.

IRONS: The Southbank Centre wants to open up even more space to even more people, and particularly young people from the surrounding area and beyond.

REEVES: But there are some other inhabitants of the Southbank site, too, who don't like the plans at all. They also see themselves as young and as artists from the grassroots. This is their lair.

HENRY EDWARDS-WOOD: I have been coming here, yeah, since I was about 12, 13. And it basically informs and directed everything about my life.

REEVES: Meet Henry Edwards-Wood. He's spokesperson for the Long Live Southbank Campaign and a lifelong skateboarder.

EDWARDS-WOOD: Everyone I know who I call a close friend, everyone I've ever lived with, my whole kind of support group, my whole family, as it were, I met here.

REEVES: Henry is sitting with his skateboard in a place called the Undercroft. Passersby strolling along the river pause and peer in as young men on skateboards leap up onto concrete blocks and down stairs. To the untutored eye, the Undercroft looks like a dark cavern, wrapped in a bright tangle of graffiti. To Henry, it's a place of learning where he mastered his art.

EDWARDS-WOOD: Literally, you'd sit in a circle and the elders of the community would just tell you about this stuff, and it was like a history lesson.

REEVES: A few decades back, the Undercroft was simply an empty pocket of concrete gloom below the Royal Festival Hall, looking out onto the river. The skateboarders rumbled in during the 1970s and took it over. Forty years on, it's hallowed ground for skateboarders everywhere, says Henry.

EDWARDS-WOOD: This is the temple of British skateboarding. It's the birthplace of British skateboarding.

REEVES: The arts in Britain are going through some tough times. Public spending cuts are taking their toll. To help fund its $190 million building project, the Southbank Centre plans to lease the Undercroft to some restaurants. That means shifting the skateboarders a little way down river.

Here to a space beneath a bridge, carrying commuter trains in and out of Charing Cross. The skateboarders are resisting with surprising resolve. They've collected tens of thousands of signatures and hired a top attorney. Henry Edwards-Wood says they intend to go to court to get the Undercroft designated an English village green.

EDWARDS-WOOD: It gives us protection, so this site is safe forever, for future generations.

REEVES: In this dispute, deep themes are in play, debates about heritage and about the validity of different forms of art. Listen to Henry Edwards-Wood defining skateboarding.

EDWARDS-WOOD: It is an art form. It is about pushing the boundaries of human achievement and what you can do, not only on a skateboard, but with your mind.

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REEVES: Step back inside the Southbank Centre, and you'll hear similar sentiments from those young jazz musicians who so badly need that extra rehearsal space. Deji Ijishakin plays clarinet. He's 14.

DEJI IJISHAKIN: Music is a language without words. You can do so many things, express so many feelings throughout it without even having to be direct. There are so many ways people can interpret music and so many ways that I can interpret music. So it's just one big inspiration.

REEVES: Back on the riverfront, at a desk set up beside the Undercroft, student and skateboard enthusiast Megan Munro is handing out stickers to passersby. For Megan, this battle is about some big principles.

MEGAN MUNRO: It's about commercialism. It's about consumerism. It's about standing up for something that, you know, you think you should have the right to anyway, you know, and not be told, oh, you've got to go over there and play in a space that we've made for you.

REEVES: So far, the Southbank's skateboarders show no sign of backing down, nor does the Southbank Centre. Artistic director Jude Kelly says if the skateboarders don't budge, the new building can't go ahead. She's in no mood to give up.

KELLY: I think it would be wrong for me to go this is a bit tough, it's getting a bit nasty, people are feeling crossed about it, let's just not bother. That would be cowardly.

REEVES: Philip Reeves, NPR News, London.

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